Abstract: Content of ATP and AMP, total intracellular pool of adenine nucleotides, the ratio of adenylate cyclase affecting ratio of ATP/ADP, energy change of the adenylate system as well as potential of adenine nucleotides phosphorylation were decreased in testicular tissue of rats with alloxan diabetes. At the same time, content of ADP and inorganic phosphate was increased as compared with control values. The data obtained suggest that energy metabolism was distinctly impaired in rat testes under conditions of alloxan diabetes, which appears to occur as a result of decrease in AMP biosynthesis and in transformation of the nucleotide into ATP during oxidative phosphorylation. These alterations in the pool of adenylates appear to play an important role in impairments of spermatogenic and endocrine functions of testes in diabetes.